Mineral material such as rock is gained from the earth for processing by exploding or excavating. Rock can also be natural and gravel or construction waste. The processing is typically crushing and/or screening of material. Mobile processing apparatuses and stationary applications are used in the processing. An excavator or wheeled loader loads the material to be processed into a feed hopper of the processing plant from where a feeder feeds the material to be processed into a jaw of a crusher or onto a screen deck. The material to be processed can also be recyclable material such as concrete, plastic, wood, metal, bricks or asphalt.
Movable material processing plants are track or wheel based and can comprise means for feeding material such as a feed hopper, a feeder, a screen and one or more conveyors for transferring the processed material for storing or further processing.
Generally the jaw crusher is used as a so called primary phase crusher in which for example stone exploded from solid rock is crushed to a more suitable particle size for a following phase processing.
Typically the jaw crusher comprises a so called fixed jaw which is attached to a body, and a pitman movable relative to an eccentric shaft, a so called movable jaw. The jaws are comprising one or more wear parts fixed onto a surface of the jaw and receiving wear and deformations due to the crushed rock.
In some cases operating problems are detected when peaks and grooves of teeth of the wear part are not staying in line with each other because moving of a wear part relative to the jaw during the crushing. Problems are among others increased side forces and an unstable quality of the crushed product. Separate centering pieces are mounted between side plates and the wear part in some crushers which pieces eliminate side clearances between the side plates and the wear part. Detaching of wear parts centered in this way may nevertheless be problematic in connection with replacement or rotation of the wear part because worn wear parts are deformed during lifetime in width and longitudinal direction. The wear parts may thus stay compressed in the body of the crusher and the detaching thereof may be difficult and time consuming.
A centering protrusion in a pitman according to prior art must be filling welded and machined from time to time because of wearing. The operation is burdensome and time consuming because one must climb into the crushing chamber of the crusher to narrow and inconvenient working conditions.
A jaw crusher is known from the publication EP 1049539 B1. A wear part fixed to a fixed jaw or a movable jaw can be a single-part or a multi-part wear part.
An object of the invention is to improve fixing of a wear part for a jaw crusher and a mineral material processing plant in order to avoid or at least minimize problems associated with the prior art.